Extended Infusion Research Articles

Evaluation of the endotoxin retention capabilities of inline intravenous filters

The capabilities of inline filters to retain bacteria and endotoxin were examined during simulated extended infusions for up to 168 hr. The tested inline filters were the ELD96 (Pall Biomedical Corp) and the IVEX 2 (Millipore Corp). Approximately 1 x 10(8) total cells of Escherichia coli B. were challenged to the upstream site of the filter. The test solution of 5% dextrose in water, 0.9% saline, Paremental A (A basic solution for total parenteral nutrition (TPN), a TPN solution in use in our clinic were infused continuously up to 168 hr and flow rate was maintained at 83 ml/hr. The effluents were analyzed using the Limulus Amebocyte Lysate (LAL) test to detect endotoxin and also passage of the challenged bacteria was tested at 24-hr intervals over 168 hr. The results were as follows: (1) The viability control culture showed the presence of viable bacteria throughout the 168-hr period of the experiment. (2) During the experiments, all filters produced sterile effluents. (3) LAL assay indicated that only the effluents from the ELD96 contained no detectable endotoxin for 168 hr.

Role of metabolic overload in the initiation of DNA synthesis following partial hepatectomy in the rat.

Changes in hepatic ATP energy charge (EC = ATP +0.5 ADP/ATP + ADP AMP) as an expression of metabolic overload and oxidative phosphorylation were studied conjointly with DNA synthesis after partial hepatectomy (PH) in the male rat. ATP and EC showed a significant decrease while mitochondrial phosphorylative activity was enhanced within 24 h. Confronted with the pattern of DNA synthesis, the above changes were clearly separated in time from the actual process of DNA synthesis. Fasting delayed the recovery of EC as well as the peak value in the rate of thymidine incorporation. Extended glucose infusion prevented the drop of ATP during the entire period of treatment and considerably reduced fat infiltration and glycogen breakdown. In these glucose-infused rats, unchanged blood sugar was associated with tendency for plasma insulin to rise and suppression of the usual posthepatectomy hyperglucagonemia. With these metabolic and hormonal changes, an important delay in the onset and modification of the whole pattern of DNA synthesis were observed. The latter process began consistently only after a late fall of ATP which followed the cessation of glucose infusion. It is suggested that changes in energy metabolism, taken as an expression of hepatocyte metabolic overload following PH, account for the early events involved in the initiation of DNA synthesis, and probably regulate hepatocyte response to systemic hepatotrophic factors.